The present invention relates to a printing apparatus including a paper feeding device for feeding individual sheets of paper one after another from a storage stacker along a first path, and further including a paper advancing device for selectively advancing to a printing assembly the sheets of paper fed along the first path or a sheet of paper of another kind fed along a second path.
In the art of a printing apparatus having a paper storage/feeder unit for storing a stack of paper on a storage tray or stacker thereof and delivering the individual sheets of paper one after another to a printing assembly of the apparatus, there has been a requirement for a so-called "interruption printing" which is performed during interruption of an ordinary printing operation on the successive sheets of paper delivered from the storage tray. Such interruption printing is effected on a sheet or sheets of paper different in size and/or format from the sheets stored in the paper storage tray. In this interruption printing, the previously established settings of right and left margin positions and tabulation positions for the ordinary printing mode must be changed to meet the specific requirement of the different sheets of paper used in the interruption printing mode. This change in the margin and tabulation settings requires subsequent re-establishment of the original settings for the ordinary printing mode of operation after the interruption printing has been completed. Thus, the printing apparatus having the paper storage/feeder unit known in the art has a problem of low printing efficiency due to requirement for considerable time and efforts to make a changeover from the ordinary printing mode to the interruption printing mode discussed above.